Johnson’s authorization of Operation Rolling Thunder expanded the previously quiet doubts and criticism into a mass movement against the war. In April 1965, Students for a Democratic Society (SDS) recruited 20,000 people for the first major antiwar protest in Washington, D.C. Thousands of students protested against Reserve Officers Training Corps (ROTC) programs, CIA and defense industry recruiters, and military research projects on their campuses. Environmentalists attacked the use of chemical weapons, such as the deadly Agent Orange.

Antiwar sentiment entered society’s mainstream. By 1968, media critics included the New York Times, the Wall Street Journal, Life magazine, and popular TV anchorman Walter Cronkite. Clergy, businesspeople, scientists, and physicians formed their own groups to pressure Johnson to stop the bombing and start negotiations. Prominent Democratic senators urged Johnson to substitute negotiation for force.

Opposition to the war took diverse forms, including letter-writing to officials, public demonstrations, draft card burnings, and attempts to stop troop trains. Although the peace movement never claimed a majority of the population, it focused media attention on the war and severely limited the administration’s options. The twenty-year-old consensus around Cold War foreign policy had shattered.

Many refused to serve. The World Boxing Association stripped Muhammad Ali of his heavyweight title when he refused to “drop bombs and bullets on brown people in Vietnam while so-called negro people in Louisville are treated like dogs.” More than 170,000 men gained conscientious objector status and performed nonmilitary duties at home or in Vietnam. About 60,000 fled the country to escape the draft, and more than 200,000 were accused of failing to register or of committing other draft offenses.

Opponents of the war held diverse views. Those who saw the conflict in moral terms wanted total withdrawal, claiming that their country had no right to interfere in a civil war and stressing the suffering of the Vietnamese people. A larger segment of antiwar sentiment reflected practical considerations—the belief that the war could not be won at a bearable cost. Those activists wanted Johnson to stop bombing North Vietnam and seek negotiations. Working-class people were no more antiwar than other groups, but they recognized the class dimensions of the war and the antiwar movement. A firefighter whose son had died in Vietnam said bitterly, “It’s people like us who give up our sons for the country.”

The antiwar movement outraged millions of Americans who supported the war. Some members of the generation who had fought against Hitler could not understand younger men’s refusal to support their government. They expressed their anger at war protesters with bumper stickers that read “America: Love It or Leave It.”

By 1967, the administration realized that “discontent with the war is now wide and deep.” President Johnson used various means to silence critics. He equated opposition to the war with communism and assistance to the enemy. His administration deceived the public by making optimistic statements and concealing officials’ doubts about the possibility of success in Vietnam. Johnson ordered the CIA to spy on peace advocates, and without the president’s specific authorization, the FBI infiltrated the peace movement, disrupted its work, and spread false information about activists. Even the resort to illegal measures failed to subdue the opposition.